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Hydrangea

Family: Hydrangeaceae Deciduous or semi-evergreen shrub
Zone 6b Save Garden

Planting Schedule

Add Hydrangea to your garden to build a schedule and get reminders.

Velvety, globe-like blooms in Hydrangea (Hydrangea macrophylla) arrive as a living bouquet—cool-toned petals that seem to hold light like satin.

Expect lush, rounded flower heads with a softly textured, slightly papery feel, carried on sturdy branches for a statuesque presence in the garden. Grow it for show-stopping ornamental color in beds, borders, and containers, where its dramatic inflorescences become the season’s centerpiece.

Light: Part SunHabit: Shrub

Botanical illustration of Hydrangea

Planting schedules and alerts are optimized for Columbus (Zone 6b).

Crop Dates

MilestoneDate
Start IndoorsDirect Sow
Last FrostApr 25th
Transplant / Sow OutdoorsApr 25th
Harvest BeginsApr 25th
Harvest EndsOct 16th

Crop Details

TraitValue
Days to MaturityN/A
Sun RequirementsPart SunPartial sun
Growth HabitShrub
Support NeededNone
Planting DepthNormal
Germination Temp (°F)65
Min Soil Temp (°F)50
Min Night Temp (°F)28
Harden Off (days)7

Frequently Asked Questions

What pest or disease commonly affects Hydrangea macrophylla, and how can I control it?
Leaf spot and powdery mildew are among the most common fungal problems on Hydrangea macrophylla, especially in humid, crowded plantings. Remove and discard infected leaves, improve airflow by spacing plants and pruning only to remove dead wood, then spray with a labeled fungicide if new growth continues to show spots or powdery growth. Check the underside of leaves for aphids and treat early with insecticidal soap to prevent honeydew and sooty mold buildup.
How often should I water Hydrangea macrophylla during active growth?
During the main growing season, keep the soil consistently moist but not waterlogged—aim for about 1 inch (2–3 cm) of water per week, adjusting for heat and rainfall. Water deeply at the base so moisture reaches the root zone, and let the top 1 inch of soil dry slightly between waterings to avoid root stress and mildew. In hot periods (or containers), you may need more frequent watering to prevent midday wilting.
How do I know when Hydrangea macrophylla is ready to harvest for blooms or cut flowers?
If you’re cutting for fresh arrangements, harvest when the flower clusters (heads) are fully colored and the bracts feel firm, not papery or shriveled. The best timing is early morning, and you’ll typically want blooms that are at peak color rather than newly opening. For continued flowering, deadhead spent heads by cutting just above a pair of healthy buds on laterals (note that bigleaf hydrangeas set many flower buds in summer for the following year).

Today's Conditions

Outdoor planting for Hydrangea in Zone 6b typically begins around 2026-04-25. Wait until soil reaches at least 50°F before transplanting Hydrangea.

Garden Alerts

In Zone 6b, the average last spring frost is around April 25. Watch soil temperature before transplanting Hydrangea.

Today's Conditions

Outdoor planting for Hydrangea in Zone 6b typically begins around 2026-04-25. Wait until soil reaches at least 50°F before transplanting Hydrangea.

Garden Alerts

In Zone 6b, the average last spring frost is around April 25. Watch soil temperature before transplanting Hydrangea.

Sowing Tips

Transplant Conditions

Wait until soil reaches 50°F and nights stay above 28°F before moving outdoors. Harden off for 7 days first.

Expert Note

Plant in partial shade and keep soil evenly moist; for bigleaf hydrangea, protect spent-bloom stems/buds over winter to preserve next season’s flowers.